The present invention relates generally to service tools to facilitate servicing of a new pressure indicating valve assembly means. The new visual pressure indicating valve means constitutes a replacement for known valve means, particularly as applied to pneumatic vehicle tires, although otherwise useful for any containers for pressurized fluid, and especially valves for introducing or releasing fluid under pressure into or from the container.
Types of valves have long been in use and are well known in the art. Restricting the present description, for simplicity, while at the same time rendering a full and complete understanding of differences existing between known types of valves and the present structure, the description of known valves will refer to those types which are currently standard in use with pneumatic vehicle tires. These include a valve stem or housing body adapted for mounting on a wheel rim, and operatively opening into the interior of an associated tire. The stem at the opposite end is open to permit tire pressure testing, introduction and/or removal of air from the tire. A valve core having a central depressable spring biased pin is operatively screw threadedly mounted within the valve stem. For this purpose the valve core has an externally threaded median portion adapted for screw threaded engagement with internal threads in the valve stem, for placement and retention therein. The spring biased central pin normally has valving means at its lower end, or at an intermediate position, which is engageable with a valve seat in the outer peripheral portion of the valve stem or housing, and through which the central pin is movably mounted.
The spring biasing means tend to hold the central pin so that valving means carried thereby is in sealing engagement with the valve seat in the valve stem. The pin is depressable either by an operator's hand digit, or some extraneous tool or piece of material to release contact between the valving means and the valve seat. Circumstances leading to such depression and disassociation include (1) introduction of air into a tire or container casing, (2) checking of pressure of a fluid such as within the container by known types of pressure gauges, and which frequently contain as a portion thereof a central pin depressor, and (3) removal of the pressurized air or fluid from the container for any desired purpose. It is further known in the art that such valve stems normally include an externally threaded upper end on which a safety cap is adapted for screw threaded engagement. It is also known in the art that means for introducing air or fluid under pressure into a container or tire will usually include, as a portion thereof, means for depressing the central pin to permit effecting a desired service.
The known types of valve cores normally include, on their upper end, upstanding lugs which are usually diametrically opposed and which are engageable by a bifurcated end tool, such as found on some tire valve safety caps or separate tools, engageable with the upstanding lugs for turning or screwing placement of, or removal of, the core from the valve stem. These known types of valve tools or implements are not optimally operable to service a pressure indicating valve means assembly of the type contemplated by the present invention.
Visual pressure indicating valve means of the type contemplated by the invention, and broadly referred to hereinabove, are disclosed generally in detail in my prior U.S. Pat. Nos. 3,717,845, 3,827,393, and 3,828,149. A further and important embodiment of a pressure indicating valve means devised and invented by the present applicant is disclosed in detail in his copending application Ser. No. 182,606, filed Aug. 29, 1980, now abandoned and entitled VEHICLE TIRE DEFLATION SIGNALING SYSTEM. The disclosures of the prior patents, and the pending application are incorporated in the present application by reference thereto.
A single embodiment of a workable structure will be shown and described in the present application for the purpose of showing and describing the design and function of such visual pressure indicating valve, and the necessity or desirability of the present service tool for facilely servicing the same. The distinction over known tools, and/or devices commonly in use in connection with known valve structures, will be obvious from the accompanying drawing, and description which follows.
Basically, the pressure indicator and valve means, which utilizes the present service tool, includes a structure having an extendable member which is actuated to extend an end visually from the valve means when air or fluid pressure within a vehicle tire, or container, reaches a point or condition lower than a desired operating condition. The visual indicating means is, in operation, visually exposed by extension from the valving means stem by operation of a spring biased or controlled poppet valve mechanism, adapted to move to an indicating position upon a predetermined decrease in pressure within the container. The indicating means is thereupon partially extended from the valving means by air pressure within the container in coaction with calibrated spring biasing means within the valving structure.
The present invention accordingly is directed to a new and novel service tool for facilely servicing a pressure indicating valve means of a new and novel construction, as regards known prior art types, and which tool has unique characteristics and features which enhance ease of servicing and use of the pressure indicating valve means.
The service tool of the invention is of a simple and inexpensive construction, and is easily operable by a user for servicing a container having operably mounted thereto a visual pressure indicating valve means as contemplated by the invention. The service tool, when pressed (friction held) or threaded on the valve will open an air flow passage greater than the flow area of a standard tire valve with its core removed.
The service tool of the invention improves tire servicing mainly in three ways:
(1) Eliminates the need to unthread and remove a valve core during tire change,
(2) Reduces possibility of creating a leak path when reinstalling a valve core that could be dirty, damaged or improperly installed, and
(3) Saves time because the tool is easier to use than standard valve core tools, and opens a greater air flow passage.